Deposition of organic films

ABSTRACT

Processes are provided herein for deposition of organic films. Organic films can be deposited, including selective deposition on one surface of a substrate relative to a second surface of the substrate. For example, polymer films may be selectively deposited on a first metallic surface relative to a second dielectric surface. Selectivity, as measured by relative thicknesses on the different layers, of above about 50% or even about 90% is achieved. The selectively deposited organic film may be subjected to an etch process to render the process completely selective. Processes are also provided for particular organic film materials, independent of selectivity.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. application Ser. No.15/170,769, filed Jun. 1, 2016, the disclosure of which is herebyincorporated by reference in its entirety for all purposes.

The present application is also related to U.S. application Ser. No.15/070,594, filed Mar. 15, 2016, entitled “VAPOR PHASE DEPOSITION OFORGANIC FILMS,” and to U.S. application Ser. No. 14/879,962, filed Oct.9, 2015, entitled “VAPOR PHASE DEPOSITION OF ORGANIC FILMS” thedisclosures of which are hereby incorporated by reference in theirentireties.

BACKGROUND Field

The present disclosure relates to deposition of organic thin films,including selective deposition on a first surface of a substraterelative to a second surface. Processes are also provided for particularorganic film materials, independent of selectivity.

Description of the Related Art

Organic thin films have valuable optical, thermal, electrical andmechanical properties and are widely used in the electronics, medicalengineering, defense, pharmaceutical, and micro- and nanotechnologyindustries. Polymers in the microelectronics and photonics industriesinclude, among other examples, photon- or electron-curable/degradablepolymers for lithographic patterning; and polyimides for packaging,interlayer dielectrics and flexible circuit boards. Norrman et al.,Annu. Rep. Prog. Chem., Sect. C, 2005, 101, 174-201.

Polymer thin films can be used, for example, as a starting point insemiconductor applications for amorphous carbon films or layers.Polyimide films are valuable for their thermal stability and resistanceto mechanical stress and chemicals. For example, polyimide films canalso be used as antireflection layers to improve pattern definition andreduce misalignment in lithography steps, as layers in multiplepatterning (e.g., SDDP, SDQP), as insulating materials for interlayerdielectric materials, as the gate dielectric in all-organic thin filmtransistors, as passivation films in packaging applications, etc.Similarly, polyamide and other organic films are valuable for theirelectrical properties and material properties for numerous applications.Polyamide films may be used, for example, as insulating materials forinterlayer dielectric materials in integrated circuit fabrication, andthe photosensitivity of polyamide through ultraviolet (UV) curing allowspatterning without separate photoresist.

Polymer thin films have traditionally been fabricated throughspin-coating techniques. The spin-coating method forms highly functionalpolymer films by coating a rotating disc with a liquid material andsintering the liquid. However, tailoring of spin-applied films islimited for several reasons. For instance, formation of uniform thinfilms on a substrate is difficult to control, in part because of theviscosity of the starting liquid, and it can be difficult to fill thegaps of very small features (e.g., trenches or gaps between metal lines)without void generation after curing. Also, spin-coating over hightopography relative to the desired thickness of the layer can result indiscontinuous and non-conformal deposition. As semiconductor chip sizescontinue to shrink, thinner and higher-strength films with more tunablemorphology are required.

Recently, vapor phase deposition processes such as chemical vapordeposition (CVD), vapor deposition polymerization (VDP), molecular layerdeposition (MLD), and sequential deposition processes such as atomiclayer deposition (ALD) and cyclical CVD have been applied to theformation of polymer thin films. In CVD, a film is deposited whenreactants react on a substrate surface. Gases of one or more reactantsare delivered to one or more substrates in a reaction chamber. Inthermal CVD, reactant gases react with one another on a hot substrate toform thin films, with the growth rate typically influenced by thetemperature and the amount of reactant supplied. In plasma enhanced CVD,one or more reactants can be activated in a remote plasma generator orin situ. CVD can be performed cyclically with intervening pauses or filmtreatments. In ALD, deposition is also conducted by cyclical exposure ofsubstrates to reactants, where films are built up throughself-saturating reactions between the substrate surface and vaporreactants performed in cycles. The substrate or wafer is exposed tovapor phase reactants, alternatingly and repeatedly, to form a thin filmof material on the substrate. In a typical process, one reactant adsorbsin a self-limiting process on the substrate. A different, subsequentlypulsed reactant reacts with the adsorbed species of the first reactantto form no more than a single molecular layer of the desired material.Thicker films are produced through repeated growth cycles until thetarget thickness is achieved. Plasma enhanced variants of ALD, andhybrid ALD/CVD processes (e.g., with some overlap of the substrateexposure to reactant supplies) are also known.

In many applications, polymer films are formed and subsequentlypatterned over a substrate. A need exists for more efficient andreliable techniques for depositing polymer films.

SUMMARY OF THE INVENTION

In some aspect, processes for selectively depositing an organic film ona substrate comprising a first surface and a second surface areprovided. In some embodiments the process may comprise one or moredeposition cycles comprising contacting the substrate with a first vaporphase precursor, and contacting the substrate with a second vapor phaseprecursor, wherein contacting the substrate with the first and secondvapor phase precursors forms the organic thin film selectively on thefirst surface relative to the second surface. In some embodimentsprocesses may further comprise repeating the contacting steps until anorganic thin film of a desired thickness has been formed. In someembodiments the first surface may be a metallic surface. In someembodiments the second surface may be a dielectric surface. In someembodiments the organic film may comprise a polyimide film. In someembodiments the substrate may be contacted with the second vapor phaseprecursor before the substrate is contacted with the first vapor phaseprecursor. In some embodiments the first vapor phase precursor maycomprise a diamine. In some embodiments the substrate is contacted withthe first vapor phase precursor comprising a diamine before it iscontacted with another, different precursor.

In some embodiments the first vapor phase precursor comprises1,6-diamnohexane (DAH). In some embodiments the second vapor phaseprecursor comprises a dianyhydride. In some embodiments the second vaporphase precursor comprises pyromellitic dianhydride (PMDA). In someembodiments the substrate is held at a temperature of greater than about170° C. during the one or more deposition cycles. In some embodimentsthe organic film comprises a polyamide film. In some embodiments thefirst vapor phase precursor comprises a halogen. In some embodiments thefirst vapor phase precursor comprises adipoyl chloride (AC). In someembodiments the second vapor phase precursor comprises a diamine. Insome embodiments the second vapor phase precursor comprises a ethylenediamine. In some embodiments the substrate is held at a temperature ofgreater than about 80° C. during the one or more deposition cycles. Insome embodiments the organic film is deposited on the first surfacerelative to the second surface with a selectivity of above about 10%. Insome embodiments the organic film is deposited on the first surfacerelative to the second surface with a selectivity of above about 50%. Insome embodiments the organic film is deposited on the first surfacerelative to the second surface with a selectivity of above about 80%. Insome embodiments the first surface comprises a metal oxide, elementalmetal, or metallic surface. In some embodiments the first surfacecomprises tungsten. In some embodiments the second surface comprisessilicon. In some embodiments the second surface comprises SiO₂. In someembodiments the process is an atomic layer deposition (ALD) typeprocess.

In some embodiments the process may further comprise subjecting thesubstrate to an etch process, wherein the etch process removessubstantially all of any deposited organic film from the second surfaceof the substrate and does not remove substantially all of the depositedorganic film from the first surface of the substrate. In someembodiments the etch process comprises exposing the substrate tohydrogen atoms, hydrogen radicals, hydrogen plasma, or combinationsthereof. In some embodiments the etch process comprises exposing thesubstrate to oxygen atoms, oxygen radicals, oxygen plasma, orcombinations thereof.

In some aspects processes for selectively depositing an organic film ona substrate comprising a first surface and a second surface areprovided. In some embodiments the processes may comprise one or moredeposition cycles comprising alternately and sequentially contacting thesubstrate with a first vapor phase precursor and a second vapor phaseprecursor, wherein the organic film is selectively formed on the firstsurface of the substrate relative to the second surface of thesubstrate. In some embodiments the first surface is a metallic surface.In some embodiments the second surface is a dielectric surface. In someembodiments the organic film is deposited on the first surface relativeto the second surface with a selectivity of above about 50%.

In some aspects processes for depositing a polyamide film on a substrateare provided. In some embodiments the processes may comprise one or moredeposition cycles comprising contacting the substrate with a first vaporphase precursor comprising 5 or fewer carbon atoms, contacting thesubstrate with a second vapor phase precursor comprising 3 or fewercarbons, and wherein contacting the substrate with the first and secondvapor phase precursors forms a polyamide film of a desired thickness. Insome embodiments the process is a vapor deposition process. In someembodiments the process is a molecular layer deposition (MLD) process.In some embodiments the substrate comprises a first surface and asecond, different surface. In some embodiments the polyamide film isformed selectively on the first surface of the substrate relative to thesecond surface of the substrate. In some embodiments the first vaporphase precursor comprises chlorine or dicarboxylic acid. In someembodiments the first vapor phase precursor comprises adipoyl chloride(AC). In some embodiments the second vapor phase precursor comprises anamine. In some embodiments the second vapor phase precursor comprisesethylene diamine (EDA).

In some aspects processes are provided for selectively forming anorganic thin film on a substrate comprising a first surface and a secondsurface. In some embodiments the processes may comprise depositing anorganic thin film on the first surface of the substrate and the secondsurface of the substrate, and exposing the deposited organic thin filmto an etchant, wherein exposing the deposited organic thin film to anetchant removes substantially all of the deposited organic thin filmfrom the second surface of the substrate and does not removesubstantially all of the deposited organic thin film from the firstsurface of the substrate. In some embodiments depositing an organic filmon the first surface of the substrate and the second surface of thesubstrate comprises selectively depositing the organic thin film on thefirst surface of the substrate relative to the second surface of thesubstrate.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a flow diagram generally illustrating processes forselectively depositing an organic film.

FIG. 2 is a flow diagram generally illustrating atomic layer deposition(ALD) processes for selectively depositing an organic film.

FIG. 3 is a flow diagram generally illustrating processes forselectively depositing an organic film on a first metallic surface of asubstrate relative to a second dielectric surface.

FIG. 4 is a series of cross-sectional scanning transmission electronmicrographs showing the thicknesses of selectively deposited polyimidefilms.

FIG. 5A is a cross-section scanning electron micrograph of a polyamidefilm deposited on a crystalline silicon substrate having a 1.5 nm nativeoxide surface.

FIG. 5B is a cross-sectional scanning electron micrograph of a polyamidefilm selectively deposited on the W surfaces of a substrate relative tothe oxide surfaces of the same substrate.

FIG. 6A is a cross-sectional scanning transmission electron micrographof a polyamide thin film selectively deposited on a W surface of asubstrate relative to a silicon oxide surface of the same substrate.

FIG. 6B is a cross-sectional scanning transmission electron micrographof a polyamide thin film selectively deposited on a W surface of asubstrate relative to a silicon oxide surface of the same substrateafter being subjected to an etching process.

FIG. 6C is a magnified view of the polyamide thin film on the W surfaceand the adjacent silicon oxide surface of FIG. 6B.

FIG. 7A is a plot showing growth rate (Å/cycle) as a function ofethylenediamine (EDA) precursor contacting time (seconds) for polyamidesample films deposited according to some embodiments.

FIG. 7B is a plot showing growth rate (Å/cycle) as a function of adipoylchloride (AC) precursor contacting time (seconds) for polyamide samplefilms deposited according to some embodiments.

FIG. 7C is a plot showing growth rate (Å/cycle) as a function ofprecursor removal time (seconds) for polyamide sample films depositedaccording to some embodiments.

FIG. 7D is a plot showing growth rate (Å/cycle) as a function ofdeposition temperature for polyamide sample films deposited according tosome embodiments.

FIG. 8A shows an ellipsometer thickness map for a polyamide filmdeposited at 71° C. according to some embodiments.

FIG. 8B shows an ellipsometer thickness map for a polyamide filmdeposited at 50° C. according to some embodiments.

DETAILED DESCRIPTION

According to some aspects of the present disclosure, selectivedeposition can be used to deposit an organic material on a first surfacerelative to a second surface. The two surfaces can have differentmaterial properties. In some embodiments an organic material isselectively deposited on a first conductive (e.g., metal or metallic)surface of a substrate relative to a second dielectric surface of thesubstrate. In some embodiments the second surface comprises —OH groups,such as a silicon oxide-based surface. In some embodiments the secondsurface may additionally comprise —H terminations, such as an HF dippedSi or HF dipped Ge surface. In such embodiments, the surface of interestwill be considered to comprise both the —H terminations and the materialbeneath the —H terminations. In some embodiments an organic materialsuch as a polyamide or polyimide is selectively deposited on a firstdielectric surface of a substrate relative to a second, differentdielectric surface. In some such embodiments, the dielectrics havedifferent compositions (e.g., silicon, silicon nitride, carbon, siliconoxide, silicon oxynitride, germanium oxide). In other such embodiments,the dielectrics can have the same basic composition (e.g., siliconoxide-based layers) but different material properties due to the mannerof formation (e.g., thermal oxides, native oxides, deposited oxides). Insome embodiments vapor deposition methods are used. In some embodimentscyclical vapor deposition is used, for example, cyclical CVD or atomiclayer deposition (ALD) processes are used. After selective deposition ofthe organic material is completed, further processing can be carried outto form the desired structures. Advantageously, selectivity can beachieved without passivation/blocking agents on the surface to receiveless of the organic layer; and/or without catalytic agents on thesurface to receive more of the organic layer.

For embodiments in which one surface comprises a metal whereas the othersurface does not, unless otherwise indicated, if a surface is referredto as a metal surface herein, it may be a metal surface or a metallicsurface. In some embodiments the metal or metallic surface may comprisemetal, metal oxides, and/or mixtures thereof. In some embodiments themetal or metallic surface may comprise surface oxidation. In someembodiments the metal or metallic material of the metal or metallicsurface is electrically conductive with or without surface oxidation. Insome embodiments metal or a metallic surface comprises one or moretransition metals. In some embodiments a metal or metallic surfacecomprises aluminum. In some embodiments the metal or metallic surfacecomprises one or more of Al, Cu, Co, Ni, W, Nb, Fe. In some embodimentsa metallic surface comprises titanium nitride. In some embodiments themetal or metallic surface comprises one or more noble metals, such asRu. In some embodiments the metal or metallic surface comprises aconductive metal oxide, nitride, carbide, boride, or combinationthereof. For example, the metal or metallic surface may comprise one ormore of RuO_(x), NbC_(x), NbB_(x), NiO_(x), CoO_(x), NbO_(x),WNC_(x),TaN, or TiN.

In some embodiments the metal or metallic surface may comprise Zn, Fe,Mn, or Mo. In some embodiments the metal or metallic surface may be anysurface that can accept or coordinate with the first or second precursorutilized in a selective deposition process as described herein.

In some embodiments an organic material is selectively deposited on ametal oxide surface relative to other surfaces. A metal oxide surfacemay be, for example a WO_(x), HfO_(x), TiO_(x), AlO_(x) or ZrO_(x)surface. In some embodiments a metal oxide surface is an oxidizedsurface of a metallic material. In some embodiments a metal oxidesurface is created by oxidizing at least the surface of a metallicmaterial using oxygen compound, such as compounds comprising O₃, H₂O,H₂O₂, O₂, oxygen atoms, plasma or radicals or mixtures thereof. In someembodiments a metal oxide surface is a native oxide formed on a metallicmaterial.

In some embodiments the first surface may comprise a passivated metalsurface, for example a passivated Cu surface. That is, in someembodiments the first surface may comprise a metal surface comprising apassivation layer, for example an organic passivation layer such as abenzotriazole (BTA) layer.

In some embodiments an organic material is selectively deposited on afirst dielectric surface relative to a second SiO₂ surface. In someembodiments an organic material is selectively deposited on a firstdielectric surface relative to a second Si or Ge surface, for example anHF-dipped Si or HF-dipped Ge surface.

In some embodiments an organic material is selectively deposited on afirst metal or metallic surface of a substrate relative to a seconddielectric surface of the substrate. In some embodiments the organicmaterial that is selectively deposited is a polyamide, polyimide, orother polymeric material. The term dielectric is used in the descriptionherein for the sake of simplicity in distinguishing from the othersurface, namely the metal or metallic surface. It will be understood bythe skilled artisan that not all non-conducting surfaces are dielectricsurfaces. For example, the metal or metallic surface may comprise anoxidized metal surface that is electrically non-conducting or has a veryhigh resistivity. Selective deposition processes taught herein candeposit on such non-conductive metallic surfaces with minimal depositionon adjacent dielectric surfaces.

In some embodiments an organic material is selectively deposited on afirst metal oxide surface of a substrate relative to a second SiO₂surface. In some embodiment the first metal oxide surface may be, forexample a WO_(x), HfO_(x), TiO_(x), AlO_(x) or ZrO_(x) surface. In someembodiments the organic material is deposited on a first dielectricsurface relative to a second SiO₂ surface. In some embodiments thesecond SiO₂ surface may be, for example, a native oxide, a thermal oxideor a chemical oxide. In some embodiments an organic material isselectively deposited on a first metal oxide surface relative to asecond Si or Ge surface, for example an HF-dipped Si or HF-dipped Gesurface.

In some embodiments a substrate is provided comprising a first metal ormetallic surface and a second dielectric surface. In some embodiments asubstrate is provided that comprises a first metal oxide surface. Insome embodiments the second surface may comprise —OH groups. In someembodiments the second surface may be a SiO₂ based surface. In someembodiments the second surface may comprise Si—O bonds. In someembodiments the second surface may comprise a SiO₂ based low-k material.In some embodiments the second surface may comprise more than about 30%,preferably more than about 50% of SiO₂. In some embodiments the secondsurface may comprise GeO₂. In some embodiments the second surface maycomprise Ge—O bonds. In some embodiments an organic material isselectively deposited on a first metal or metallic surface relative to asecond Si or Ge surface, for example an HF-dipped Si or HF-dipped Gesurface.

In certain embodiments the first surface may comprise a silicon dioxidesurface and the second dielectric surface may comprise a second,different silicon dioxide surface. For example, in some embodiments thefirst surface may comprise a naturally or chemically grown silicondioxide surface. In some embodiments the second surface may comprise athermally grown silicon dioxide surface. In other embodiments, the firstor the second surface may be replaced with a deposited silicon oxidelayer. Therefore, in some embodiments organic material may beselectively deposited on a first silicon dioxide surface of a substraterelative to a second silicon dioxide surface that was formed by adifferent technique and therefore has different material properties.

In some embodiments the substrate may be pretreated or cleaned prior toor at the beginning of the selective deposition process. In someembodiments the substrate may be subjected to a plasma cleaning processat prior to or at the beginning of the selective deposition process. Insome embodiments a plasma cleaning process may not include ionbombardment, or may include relatively small amounts of ion bombardment.For example, in some embodiments the substrate surface may be exposed toplasma, radicals, excited species, and/or atomic species prior to or atthe beginning of the selective deposition process. In some embodimentsthe substrate surface may be exposed to hydrogen plasma, radicals, oratomic species prior to or at the beginning of the selective depositionprocess. In some embodiments a pretreatment or cleaning process may becarried out in the same reaction chamber as a selective depositionprocess, however in some embodiments a pretreatment or cleaning processmay be carried out in a separate reaction chamber.

The term “about” is employed herein to mean within standard measurementaccuracy.

Selective deposition using the methods described herein canadvantageously be achieved without treatment of the second dielectricsurface to block deposition thereon and/or without treatment of thefirst surface (whether metallic or a different dielectric surface) tocatalyze deposition. As a result, in some embodiments the seconddielectric surface does not comprise a passivation or blocking layer,such as a self-assembled monolayer (SAM), which would prevent the actualtop surface of the second dielectric surface from being exposed to thechemicals of the deposition processes described herein. Thus, in someembodiments selectivity is achieved despite the lack of blocking orcatalyzing agents, and both first and second surfaces are directlyexposed to the deposition reactants.

Vapor phase deposition techniques can be applied to organic films andpolymers such as polyimide films, polyamide films, polyurea films,polyurethane films, polythiophene films, and more. CVD of polymer filmscan produce greater thickness control, mechanical flexibility, conformalcoverage, and biocompatibility as compared to the application of liquidprecursor. Sequential deposition processing of polymers can produce highgrowth rates in small research scale reactors. Similar to CVD,sequential deposition processes can produce greater thickness control,mechanical flexibility, and conformality. The terms “sequentialdeposition” and “cyclical deposition” are employed herein to apply toprocesses in which the substrate is alternately or sequentially exposedto different precursors, regardless of whether the reaction mechanismsresemble ALD, CVD, MLD or hybrids thereof.

In some embodiments the processes described herein may be batchprocesses, that is, the processes may be carried out on two or moresubstrates at the same time. In some embodiments the processes describedherein may be carried out on two or more, five or more, 10 or more, 25or more, 50 or more, or 100 or more substrates at the same time. In someembodiments the substrate may comprise wafers, for example,semiconductor or silicon wafers. In some embodiments the substrates mayhave diameters of 100 mm or more, 200 mm or more, or 300 mm or more. Insome instances substrates having diameters of 450 mm or more may bedesirable.

Selectivity

Selectivity can be given as a percentage calculated by [(deposition onfirst surface)−(deposition on second surface)]/(deposition on the firstsurface). Deposition can be measured in any of a variety of ways. Insome embodiments deposition may be given as the measured thickness ofthe deposited material. In some embodiments deposition may be given asthe measured amount of material deposited.

In some embodiments selectivity is greater than about 10%, greater thanabout 50%, greater than about 75%, greater than about 85%, greater thanabout 90%, greater than about 93%, greater than about 95%, greater thanabout 98%, greater than about 99% or even greater than about 99.5%. Inembodiments described herein, the selectivity can change over theduration or thickness of a deposition. Surprisingly, selectivity hasbeen found to increase with the duration of the deposition for the vaporphase polymer film depositions described herein. In contrast, typicalselective deposition based on differential nucleation on differentsurfaces tends to become less selective with greater duration orthickness of a deposition.

In some embodiments deposition only occurs on the first surface and doesnot occur on the second surface. In some embodiments deposition on thefirst surface of the substrate relative to the second surface of thesubstrate is at least about 80% selective, which may be selective enoughfor some particular applications. In some embodiments the deposition onthe first surface of the substrate relative to the second surface of thesubstrate is at least about 50% selective, which may be selective enoughfor some particular applications. In some embodiments the deposition onthe first surface of the substrate relative to the second surface of thesubstrate is at least about 10% selective, which may be selective enoughfor some particular applications.

In some embodiments the organic film deposited on the first surface ofthe substrate may have a thickness less than about 50 nm, less thanabout 20 nm, less than about 10 nm, less than about 5 nm, less thanabout 3 nm, less than about 2 nm, or less than about 1 nm, while a ratioof material deposited on the first surface of the substrate relative tothe second surface of the substrate may be greater than or equal toabout 2:1, greater than or equal to about 20:1, greater than or equal toabout 15:1, greater than or equal to about 10:1, greater than or equalto about 5:1, greater than or equal to about 3:1, or greater than orequal to about 2:1.

In some embodiments the selectivity of the selective depositionprocesses described herein may depend on the materials which comprisethe first and/or second surface of the substrate. For example, in someembodiments where the first surface comprises a BTA passivated Cusurface and the second surface comprises a natural or chemical silicondioxide surface the selectivity may be greater than about 8:1 or greaterthan about 15:1. In some embodiments where the first surface comprises ametal or metal oxide and the second surface comprises a natural orchemical silicon dioxide surface the selectivity may be greater thanabout 5:1 or greater than about 10:1. In some embodiments where thefirst surface comprises a chemical or natural silicon dioxide surfaceand the second surface comprises a thermal silicon dioxide surface theselectivity may be greater than about 5:1 or greater than about 10:1. Insome embodiments where the first surface comprises natural or chemicalsilicon dioxide, and the second surface comprises Si—H terminations, forexample an HF dipped Si surface , the selectivity may be greater thanabout 5:1 or greater than about 10:1. In some embodiments where thefirst surface comprises Si—H terminations, for example an HF dipped Sisurface, and the second surface comprises thermal silicon dioxide, theselectivity may be greater than about 5:1 or greater than about 10:1.

Selective Deposition

Deposition processes taught herein can achieve high growth rate andthroughput, and can produce high quality organic thin films.

In some embodiments, a substrate comprising a first surface and a secondsurface is provided. The first and second surfaces may have differentmaterial properties. In some embodiments the first surface may be ametallic surface and the second surface may be a dielectric surface. Insome embodiments a first organic reactant is vaporized to form a firstreactant vapor. The reactant being vaporized may be liquid or solidunder standard temperature and pressure conditions (room temperature andatmospheric pressure). In some embodiments, the reactant being vaporizedcomprises an organic precursor, such as an amine, for example a diamine,such as 1,6-diamnohexane (DAH), or another organic precursor, such as adianhydride, for example pyromellitic dianhydride (PMDA). The substrateis then exposed to the first reactant vapor and an organic filmdeposited. The method can include additional steps, and may be repeated,but need not be performed in the illustrated sequence nor the samesequence in each repetition if repeated, and can be readily extended tomore complex vapor deposition techniques.

In some embodiments, the organic film comprises a polymer. In someembodiments, the polymer deposited is a polyimide. In some embodiments,the polymer deposited is a polyamide. Other examples of depositedpolymers include dimers, trimers, polyurethanes, polythioureas,polyesters, polyimines, other polymeric forms or mixtures of the abovematerials.

The techniques taught herein can be applied to vapor depositiontechniques, including CVD, VPD, ALD, and MLD in a wide variety ofreactor configurations.

Referring to FIG. 1 and in some embodiments, a substrate comprising afirst surface and a second surface is provided at block 11. The firstand second surfaces may have different material properties. In someembodiments the first surface may be a conductive surface, for example ametal or metallic surface, and the second surface may be a dielectricsurface. In some embodiments the first surface may be a dielectricsurface and the second surface may be a second, different dielectricsurface. In some embodiments the first and second surfaces may have thesame basic composition, but may have different material properties dueto different manners of formation (e.g., thermal oxide, deposited oxide,native oxide).

In some embodiments the first precursor may be vaporized at a firsttemperature to form the first vapor phase precursor. In some embodimentsthe first precursor vapor is transported to the substrate through a gasline at a second temperature. In some embodiments the secondtransportation temperature is higher than the first vaporizationtemperature. In some embodiments the substrate is contacted with a firstvapor phase precursor, or reactant, at block 12 for a first exposureperiod. In some embodiments the substrate may be contacted with thefirst vapor phase precursor at a third temperature that is higher thanthe first temperature.

In some embodiments the first precursor exposure period is from about0.01 seconds to about 60 seconds, about 0.05 seconds to about 30seconds, about 0.1 seconds to about 10 seconds or about 0.2 seconds toabout 5 seconds. The optimum exposure period can be readily determinedby the skilled artisan based on the particular circumstances. In someembodiments where batch reactors may be used, exposure periods ofgreater than 60 seconds may be employed.

In some embodiments the substrate is contacted with a second vapor phaseprecursor, or reactant, at block 13 for a second exposure period. Insome embodiments the second precursor may be vaporized at a fourthtemperature to form the second vapor phase precursor. In someembodiments the second reactant vapor is transported to the substratethrough a gas line at a second temperature. In some embodiments thefifth transportation temperature is higher than the first vaporizationtemperature. In some embodiments the substrate may be contacted with thesecond vapor phase precursor at a sixth temperature that is higher thanthe fourth temperature. In some embodiments the sixth temperature may besubstantially the same as the third temperature at which the first vaporphase precursor contacts the substrate.

In some embodiments the second precursor exposure period is from about0.01 seconds to about 60 seconds, about 0.05 seconds to about 30seconds, about 0.1 seconds to about 10 seconds or about 0.2 seconds toabout 5 seconds. The optimum exposure period can be readily determinedby the skilled artisan based on the particular circumstances. In someembodiments where batch reactors may be used, exposure periods ofgreater than 60 seconds may be employed.

In block 14 an organic film is selectively deposited on the firstsurface relative to the second surface. The skilled artisan willappreciate that selective deposition of an organic film is the result ofthe above-described contacting actions, 12-13, rather than a separateaction. In some embodiments, the above-described contacting actions,blocks 12-13, may be considered a deposition cycle. In some embodimentsa deposition cycle may repeated until an organic film of a desiredthickness is selectively deposited. Such a selective deposition cyclecan be repeated until a film of sufficient thickness is left on thesubstrate (block 15) and the deposition is ended (block 16). Theselective deposition cycle can include additional acts, need not be inthe same sequence nor identically performed in each repetition, and canbe readily extended to more complex vapor deposition techniques. Forexample, a selective deposition cycle can include additional reactantsupply processes, such as the supply and removal (relative to thesubstrate) of additional reactants in each cycle or in selected cycles.Though not shown, the process may additionally comprise treating thedeposited film to form a polymer (for example, UV treatment, annealing,etc.). [0051] Referring to FIG. 2 and in some embodiments, a substratecomprising a first surface and a second surface is provided at block 21.The first and second surfaces may have different material properties. Insome embodiments the first surface may be a conductive surface, forexample a metal or metallic surface, and the second surface may be adielectric surface. In some embodiments the first surface may be adielectric surface and the second surface may be a second, differentdielectric surface. In some embodiments the first and second surfacesmay have the same basic composition, but may have different materialproperties due to different manners of formation (e.g., thermal oxide,deposited oxide, native oxide).

In some embodiments a sequential deposition method for selective vapordeposition of an organic film comprises vaporizing a first organicprecursor is at a first temperature to form a first precursor vapor atblock 22. In some embodiments the first precursor vapor is transportedto the substrate through a gas line at a second temperature. In someembodiments the second transportation temperature is higher than thefirst vaporization temperature. In some embodiments the substrate iscontacted with the vapor phase first precursor for a first exposureperiod at block 23. In some embodiments, the first precursor, or speciesthereof, chemically adsorbs on the substrate in a self-saturating orself-limiting fashion. The gas line can be any conduit that transportsthe first precursor vapor from the source to the substrate. In someembodiments, the substrate may be exposed to the first precursor vaporat a third temperature that is higher than the first temperature.

In some embodiments the first precursor exposure period is from about0.01 seconds to about 60 seconds, about 0.05 seconds to about 30seconds, about 0.1 seconds to about 10 seconds or about 0.2 seconds toabout 5 seconds. The optimum exposure period can be readily determinedby the skilled artisan based on the particular circumstances. In someembodiments where batch reactors may be used, exposure periods ofgreater than 60 seconds may be employed.

Excess of the first precursor vapor (and any volatile reactionby-products) may then be removed from contact with the substrate atblock 24. Such removal can be accomplished by, for example, purging,pump down, moving the substrate away from a chamber or zone in which itis exposed to the first reactant, or combinations thereof. In someembodiments a first precursor removal period, for example a purgeperiod, is from about 0.01 seconds to about 60 seconds, about 0.05seconds to about 30 seconds, about 0.1 seconds to about 10 seconds orabout 0.2 seconds to about 5 seconds. The optimum removal period can bereadily determined by the skilled artisan based on the particularcircumstances. In some embodiments where batch reactors may be used,removal periods of greater than 60 seconds may be employed.

In some embodiments the second precursor may be vaporized at a fourthtemperature to form the second vapor phase precursor at block 25. Insome embodiments the second reactant vapor is transported to thesubstrate through a gas line at a second temperature. In someembodiments the fifth transportation temperature is higher than thefirst vaporization temperature. In some embodiments the substrate may becontacted with the second vapor phase precursor at a sixth temperaturethat is higher than the fourth temperature. In some embodiments thesixth temperature may be substantially the same as the third temperatureat which the first vapor phase precursor contacts the substrate. In someembodiments the substrate may exposed to a second precursor vapor for asecond exposure period at block 26. In some embodiments, the secondreactant may react with the adsorbed species of the first reactant onthe substrate.

In some embodiments the first precursor exposure period is from about0.01 seconds to about 60 seconds, about 0.05 seconds to about 30seconds, about 0.1 seconds to about 10 seconds or about 0.2 seconds toabout 5 seconds. The optimum exposure period can be readily determinedby the skilled artisan based on the particular circumstances. In someembodiments where batch reactors may be used, exposure periods ofgreater than 60 seconds may be employed.

In some embodiments excess of the second precursor vapor (and anyvolatile reaction by-product) is removed from contact with the substrateat block 27, such that the first reactant vapor and the second reactantvapor do not mix. In some embodiments the vapor deposition process ofthe organic film does not employ plasma and/or radicals, and can beconsidered a thermal vapor deposition process. In some embodiments asecond precursor removal period, for example a purge period, is fromabout 0.01 seconds to about 60 seconds, about 0.05 seconds to about 30seconds, about 0.1 seconds to about 10 seconds or about 0.2 seconds toabout 5 seconds. The optimum removal period can be readily determined bythe skilled artisan based on the particular circumstances. In someembodiments where batch reactors may be used, removal periods of greaterthan 60 seconds may be employed.

In block 28 an organic film is selectively deposited on the firstsurface relative to the second surface. The skilled artisan willappreciate that selective deposition of an organic film is the result ofthe above-described contacting actions rather than a separate action. Insome embodiments, the above-described contacting and removing (and/orhalting supply) actions, blocks 23-27, may be considered a depositioncycle. In some embodiments a deposition cycle may repeated until anorganic film of a desired thickness is selectively deposited. Such aselective deposition cycle can be repeated (block 29) until a film ofsufficient thickness is left on the substrate and the deposition isended (block 30). The selective deposition cycle can include additionalacts, need not be in the same sequence nor identically performed in eachrepetition, and can be readily extended to more complex vapor depositiontechniques. For example, a selective deposition cycle can includeadditional reactant supply processes, such as the supply and removal ofadditional reactants in each cycle or in selected cycles. Though notshown, the process may additionally comprise treating the deposited filmto form a polymer (for example, UV treatment, annealing, etc.).

Referring to FIG. 3, and in some embodiments, a substrate comprising afirst metal or metallic surface and a second dielectric surface isprovided at block 31. In some embodiments the metal or metallic surfacemay comprise metal, metal oxides, and/or mixtures thereof. In someembodiments the metal or metallic surface may comprise surfaceoxidation. In some embodiments the metal or metallic material of themetal or metallic surface is electrically conductive with or withoutsurface oxidation. In some embodiments the first surface may comprise apassivated metal surface, for example a passivated Cu surface.

In some embodiments the second dielectric surface may comprise siliconoxide. The term dielectric is used herein for the sake of simplicity indistinguishing from the other surface, namely the metal or metallicsurface. Unless indicated otherwise with respect to particularembodiments, the term dielectric in the context of this application canbe understood to cover all surfaces which are electricallynon-conducting or have very high resistivity. In some embodiments thesecond surface may comprise —OH groups. In some embodiments the secondsurface may be a SiO₂ based surface. In some embodiments the secondsurface may comprise Si—O bonds. In some embodiments the second surfacemay comprise a SiO₂ based low-k material. In some embodiments the secondsurface may comprise more than about 30%, preferably more than about 50%of SiO₂. In some embodiments the second surface may comprise GeO₂. Insome embodiments the second surface may comprise Ge—O or Ge—OH bonds.

In some embodiments the first precursor may be vaporized at a firsttemperature to form the first vapor phase precursor. In some embodimentsthe first precursor vapor is transported to the substrate through a gasline at a second temperature. In some embodiments the secondtransportation temperature is higher than the first vaporizationtemperature. In some embodiments the substrate is contacted with a firstvapor phase precursor, or reactant, at block 32 for a first exposureperiod. In some embodiments the substrate may be contacted with thefirst vapor phase precursor at a third temperature that is higher thanthe first temperature.

In some embodiments the first precursor exposure period is from about0.01 seconds to about 60 seconds, about 0.05 seconds to about 30seconds, about 0.1 seconds to about 10 seconds or about 0.2 seconds toabout 5 seconds. The optimum exposure period can be readily determinedby the skilled artisan based on the particular circumstances. In someembodiments where batch reactors may be used, exposure periods ofgreater than 60 seconds may be employed.

In some embodiments the substrate is contacted with a second vapor phaseprecursor, or reactant, at block 33 for a second exposure period. Insome embodiments the second precursor may be vaporized at a fourthtemperature to form the second vapor phase precursor. In someembodiments the second reactant vapor is transported to the substratethrough a gas line at a second temperature. In some embodiments thefifth transportation temperature is higher than the first vaporizationtemperature. In some embodiments the substrate may be contacted with thesecond vapor phase precursor at a sixth temperature that is higher thanthe fourth temperature. In some embodiments the sixth temperature may besubstantially the same as the third temperature at which the first vaporphase precursor contacts the substrate.

In some embodiments the second precursor exposure period is from about0.01 seconds to about 60 seconds, about 0.05 seconds to about 30seconds, about 0.1 seconds to about 10 seconds or about 0.2 seconds toabout 5 seconds. The optimum exposure period can be readily determinedby the skilled artisan based on the particular circumstances. In someembodiments where batch reactors may be used, exposure periods ofgreater than 60 seconds may be employed.

In block 34 an organic film is selectively deposited on the firstmetallic surface relative to the second dielectric surface. The skilledartisan will appreciate that selective deposition of an organic film isthe result of the above-described contacting actions rather than aseparate action. In some embodiments, the above-described contactingactions, blocks 32-33, may be considered a deposition cycle. In someembodiments a deposition cycle may repeated until an organic film of adesired thickness is selectively deposited on the first metallic surfaceof the substrate relative to the second dielectric surface. Such aselective deposition cycle can be repeated until a film of sufficientthickness is left on the first metallic surface of the substrate (block35) and the deposition is ended (block 36). The selective depositioncycle can include additional acts, need not be in the same sequence noridentically performed in each repetition, and can be readily extended tomore complex vapor deposition techniques. For example, a selectivedeposition cycle can include additional reactant supply processes, suchas the supply and removal of additional reactants in each cycle or inselected cycles. Though not shown, the process may additionally comprisetreating the deposited film to form a polymer (for example, UVtreatment, annealing, etc.).

Various reactants can be used for the above described processes. Forexample, in some embodiments, the first precursor or reactant is anorganic reactant such as a diamine, e.g., 1,6-diamnohexane (DAH), or anyother monomer with two reactive groups.

In some embodiments, the second reactant or precursor is also an organicreactant capable of reacting with adsorbed species of the first reactantunder the deposition conditions. For example, the second reactant can bean anhydride, such as furan-2,5-dione (maleic acid anhydride), or moreparticularly a dianhydride, e.g., pyromellitic dianhydride (PMDA), orany other monomer with two reactive groups which will react with thefirst reactant.

In some embodiments the substrate is contacted with the first precursorprior to being contacted with the second precursor. Thus, in someembodiments the substrate is contacted with an amine, such as a diamine,for example 1,6-diamnohexane (DAH) prior to being contacted with anotherprecursor. However, in some embodiments the substrate may be contactedwith the second precursor prior to being contacted with the firstprecursor. Thus, in some embodiments the substrate is contacted with ananhydride, such as furan-2,5-dione (maleic acid anhydride), or moreparticularly a dianhydride, e.g., pyromellitic dianhydride (PMDA) priorto being contacted with another precursor.

Although the above described processes begin with contacting thesubstrate with the first vapor phase precursor, in other embodiments aprocess may begin with contacting the substrate with the second vaporphase precursor. It will be understood by the skilled artisan thatcontacted the substrate with the first precursor and second precursorare interchangeable in the processes described herein.

In some embodiments, different reactants can be used to tune the filmproperties. For example, a polyimide film could be deposited using4,4′-oxydianiline or 1,4-diaminobenzene instead of 1,6-diaminohexane toget a more rigid structure with more aromaticity and increased dry etchresistance.

In some embodiments the reactants do not contain metal atoms. In someembodiments the reactants do not contain semimetal atoms. In someembodiments one of the reactants comprises metal or semimetal atoms. Insome embodiments the reactants contain carbon and hydrogen and one ormore of the following elements: N, O, S, P or a halide, such as Cl or F.In some embodiments the first reactant may comprise, for example,adipoyl chloride (AC).

Deposition conditions can differ depending upon the selected reactantsand can be optimized upon selection. In some embodiments the reactiontemperature can be selected from the range of about 80° C. to about 250°C. In some embodiments, for example where the selectively depositedorganic film comprises polyimide, the reaction temperature can beselected from the range of about 170° C. to about 210° C. In someembodiments, for example where the selectively deposited organic filmcomprises polyamide, the reaction temperature can be selected from arange of about 80° C. to about 150° C. In some embodiments where theselectively deposited organic film comprises polyimide the reactiontemperature may be greater than about 160° C., 180° C., 190° C., 200°C., or 210° C. In some embodiments where the selectively depositedorganic film comprises polyamide the reaction temperature may be greaterthan about 80° C., 90° C., 100° C., 110° C., 120° C., 130° C., 140° C.,or 150° C.

In some embodiments the reaction chamber pressure may be from about 1mTorr to about 1000 Torr.

For example, for sequential deposition of polyimide using PMDA and DAHin a single wafer deposition tool, substrate temperatures can beselected from the range of about 150° C. to about 250° C., or from about170° C. to about 210° C., and pressures can be selected from the rangeof about 1 mTorr to about 760 Torr, more particularly between about 100mTorr to about 100 Torr.

In some embodiments the selectively deposited or formed organic filmdoes not contain metal atoms. In some embodiments the selectivelydeposited or formed organic film does not contain semimetal atoms. Insome embodiments the selectively deposited or formed organic filmcontains metal or semimetal atoms. In some embodiments the selectivelydeposited or formed organic film contains carbon and hydrogen and one ormore of the following elements: N, O, S, or P.

Examples of suitable reactors that may be used in the selectivedeposition processes described herein include commercially available ALDequipment such as the F-120® reactor, Pulsar® reactor, such as a Pulsar3000® or Pulsar 2000®, and Advance® 400 Series reactor, available fromASM America, Inc. of Phoenix, Ariz. and ASM Europe B.V., Almere,Netherlands. In addition to these ALD reactors, many other kinds ofreactors capable growth of organic thin films, including CVD reactors,VDP reactors, and MLD reactors can be employed.

In some embodiments a suitable reactor may be a batch reactor and maycontain two or more substrates. In some embodiments the substrate maycomprise, for example, wafers. In some embodiments a suitable reactormay be a batch reactor that may contain two or more, five or more, 10 ormore, 25 or more, 50 or more, or 100 or more substrates. In someembodiments the substrate may comprise wafers, for example,semiconductor or silicon wafers. In some embodiments the substrates mayhave diameters of 100 mm or more, 200 mm or more, or 300 mm or more. Insome instances substrates having diameters of 450 mm or more may bedesirable.

In some embodiments the first surface (e.g., metallic surface) of asubstrate onto which an organic film is to be selectively deposited maycomprise a structure on a semiconductor substrate or integrated circuitworkpiece. In some embodiments the first surface of the substrate maycomprise one or more metal lines or dots. For example, the first surfaceof the substrate may comprise a W or Cu line while the second surfacemay comprise a silicon oxide-based material. That is, in someembodiments the substrate may comprise at least a first portion of thefirst metallic surface and a second portion of the first metallicsurface, wherein the first and second portions of the first metallicsurface are separated on the substrate by the second dielectric surface.

In some embodiments, the selectivity of the selective depositionprocesses described herein may change based on the dimensions or pitchof the portions of the first surface onto which the organic film isselectively deposited. In some embodiments the selectivity of theselective deposition processes described herein may increase as thepitch of the features comprising first surface increases. Increasedpitch is used herein as conventional in the semiconductor industry tomean greater number of features in a given dimension, or greater densityand closer spacing between features.

In some embodiments a selective deposition process can achieve a desiredselectivity on a substrate wherein the periodicity of featurescomprising the first surface is less than about 1 micron, preferablyless than about 500 nm, preferably less than about 250 nm, and mostpreferably less than about 100 nm. In some embodiments the periodicityof features comprising the first surface is less than 40 nm, or evenless than 20 nm. As used herein, periodicity refers to the distancebetween the two nearest repeated structures, materials, or surfaces on asubstrate. In some embodiments the selectivity of a selective depositionprocess may depend on the distance between a first portion of thesubstrate comprising a first surface and a second portion of thesubstrate comprising a first surface, such as the aforementionedperiodicity for repeating patterns on a substrate. In some embodimentsthe selectivity of the selective deposition processes described hereinmay increase as the distance between the portions of the first materialdecreases.

In some embodiments a selective deposition process can achieve a desiredselectivity on a substrate comprising a first portion of the firstsurface separated by a distance from a second portion of the firstsurface. In some embodiments the desired selectivity may be achievedwhen the distance between the first and second portions of the firstsurface is less than about 1 micron, preferably less than about 500 nm,preferably less than about 250 nm, and most preferably less than about100 nm.

In some embodiments the selectivity of a selective deposition processmay be related to the number of growth, or deposition cycles performedin the selective deposition process. In some embodiments the selectivityfor a selective deposition process may increase with the number ofdeposition cycles. For example, the selectivity of a selectivedeposition process comprising 250 of deposition cycles may be less thanthe selectivity of a selective deposition process comprising 1000deposition cycles where the conditions for the deposition cycles in eachprocess are substantially the same. This is surprising, given thattypical selective vapor deposition processes tend to lose selectivitywith greater thickness or deposition duration.

In some embodiments an increase in the number of deposition cycles in aselective deposition process may result in a corresponding increase inthe selectivity of the process. For example, in some embodimentsdoubling the number of deposition cycles may result in selectivedeposition process which is twice as selective, as will be understoodfrom the example of FIG. 4.

Although generally a deposition or reaction temperature for theselective deposition processes described herein is greater than or equalto the vaporization temperatures of the first and second reactants, insome other embodiments the reaction temperature may be lower than one orboth of the reactant vaporization temperatures.

Precursors

Various reactants can be used to deposit polyamide or polyimide filmsaccording to the processes described herein. For example, in someembodiments the first precursor or reactant is an amine, for example adiamine. In some embodiments the first reactant can be, for example,1,6-diamnohexane (DAH). In some embodiments the substrate the substrateis contacted with the first precursor before it is contacted with thesecond precursor. Thus, in some embodiments the substrate may becontacted with an amine, such as a diamine, before it is contacted witha second precursor.

In some embodiments, the second reactant or precursor is also an organicreactant capable of reacting with adsorbed species of the first reactantunder the deposition conditions. For example, in some embodiments, thesecond precursor or reactant is an organic reactant such as ananhydride, such as furan-2,5-dione (maleic acid anhydride). Theanhydride can be a dianhydride, e.g., pyromellitic dianhydride (PMDA).In some embodiments the second reactant can be any other monomer withtwo reactive groups which will react with the first reactant.

In some embodiments the reactants do not contain metal atoms. In someembodiments the reactants do not contain semimetal atoms. In someembodiments one of the reactants comprises metal or semimetal atoms. Insome embodiments the reactants contain carbon and hydrogen and one ormore of the following elements: N, O, S, P or a halide, such as Cl or F.In some embodiments the first reactant may comprise, for example,adipoyl chloride (AC).

In some embodiments reactants for use in the selective depositionprocesses described herein may have the general formula:

R¹(NH₂)₂   (1)

Wherein R¹ may be an aliphatic carbon chain comprising 1-5 carbon atoms,2-5 carbon atoms, 2-4 carbon atoms, 5 or fewer carbon atoms, 4 or fewercarbon atoms, 3 or fewer carbon atoms, or 2 carbon atoms. In someembodiments the bonds between carbon atoms in the reactant or precursormay be single bonds, double bonds, triple bonds, or some combinationthereof. Thus, in some embodiments a reactant may comprise two aminogroups. In some embodiments the amino groups of a reactant may occupyone or both terminal positions on an aliphatic carbon chain. However, insome embodiments the amino groups of a reactant may not occupy eitherterminal position on an aliphatic carbon chain. In some embodiments areactant may comprise a diamine. In some embodiments a reactant maycomprise an organic precursor selected from the group of1,2-diaminoethane (1), 1,3-diaminopropane (1), 1,4-diaminobutane (1),1,5-diaminopentane (1), 1,2-diaminopropane (1), 2,3-butanediamine,2,2-dimethyl-1,3-propanediamine (1).

In some embodiments reactants for use in the selective depositionprocesses described herein may have the general formula:

R²(COCl)₂   (2)

Wherein R² may be an aliphatic carbon chain comprising 1-3 carbon atoms,2-3 carbon atoms, or 3 or fewer carbon atoms. In some embodiments thebonds between carbon atoms in the reactant or precursor may be singlebonds, double bonds, triple bonds, or some combination thereof. In someembodiments a reactant may comprise a chloride. In some embodiments areactant may comprise a diacyl chloride. In some embodiments a reactantmay comprise an organic precursor selected from the group of oxalylchloride (I), malonyl chloride, and fumaryl chloride.

In some embodiments, a reactant comprises an organic precursor selectedfrom the group of 1,4-diisocyanatobutane or 1,4-diisocyanatobenzene. Insome embodiments a reactant comprises an organic precursor selected fromthe group of terephthaloyl dichloride, alkyldioyl dichlorides, such ashexanedioyl dichloride, octanedioyl dichloride, nonanedioyl dichloride,decanedioyl dichloride, or terephthaloyl dichloride. In someembodiments, a reactant comprises an organic precursor selected from thegroup of 1,4-diisothiocyanatobenzene or terephthalaldehyde. In someembodiments, a reactant being vaporized can be also a diamine, such as1,4-diaminobenzene, decane-1,10-diamine, 4-nitrobenzene-1,3-diamine,4,4′-oxydianiline, or ethylene diamine. In some embodiments, a reactantcan be a terephthalic acid bis(2-hydroxyethyl) ester. In someembodiments a reactant can be a carboxylic acid, for example alkyl-,alkenyl-, alkadienyl-dicarboxylic or tricarboxylic acid, such asethanedioic acid, propanedioic acid, butanedioic acid, pentanedioic acidor propane-1,2,3-tricarboxylic acid. In some embodiments, a reactant canbe an aromatic carboxylic or dicarboxylic acid, such as benzoic acid,benzene-1,2-dicarboxylic acid, benzene-1,4-dicarboxylic acid orbenzene-1,3-dicarboxylic acid. In some embodiments, a reactant maycomprise one or more OH-groups bonded to a hydrocarbon. In someembodiments, a reactant can be selected from the group of diols, triols,aminophenols such as 4-aminophenol, benzene-1,4-diol orbenzene-1,3,5-triol. In some embodiments, a reactant can be8-quinolinol. In some embodiments, the reactant can comprisealkenylchlorosilanes, like alkenyltrichlorosilanes, such as7-octenyltrichlorosilane.

In some embodiments a reactant may have a vapor pressure greater thanabout 0.5 Torr, 0.1 Torr, 0.2 Torr, 0.5 Torr, 1 Torr or greater at atemperature of about 20° C. or room temperature. In some embodiments areactant may have a boiling point less than about 400° C. , less than300° C., less than about 250° C., less than about 200° C., less thanabout 175° C., less than about 150° C., or less than about 100° C.

Polyamide Deposition

In some embodiments deposition processes taught herein may comprisedeposition of a polyamide thin film. In some embodiments such adeposition process may comprise a vapor deposition process. In someembodiments such a deposition process may comprise a molecular layerdeposition (MLD) process. In some embodiments such deposition processesmay be a selective deposition process. However, in some embodiments sucha deposition processes may be a nonselective deposition process. In someembodiments a first organic reactant is vaporized to form a firstprecursor vapor. The reactant being vaporized may be liquid or solidunder standard temperature and pressure conditions (room temperature andatmospheric pressure). In some embodiments, the first reactant beingvaporized comprises an organic precursor, such as an organochloride, forexample adipoyl chloride (AC). In some embodiments a reactant maycomprise an organic precursor selected from the group of oxalyl chloride(I), malonyl chloride, and fumaryl chloride.

In some embodiments the first precursor may be vaporized at a firsttemperature to form the first vapor phase precursor. In some embodimentsthe first precursor vapor is transported to the substrate through a gasline at a second temperature. In some embodiments the secondtransportation temperature is higher than the first vaporizationtemperature. In some embodiments the substrate is contacted with a firstvapor phase precursor, or reactant, for a first exposure period. In someembodiments the substrate may be contacted with the first vapor phaseprecursor at a third temperature that is higher than the firsttemperature.

In some embodiments the first precursor exposure period is from about0.05 seconds to about 5.0 seconds, about 0.1 seconds to about 3 secondsor about 0.2 seconds to about 1.0 seconds. The optimum exposure periodcan be readily determined by the skilled artisan based on the particularcircumstances.

In some embodiments a second organic reactant is vaporized to form asecond precursor vapor. The reactant being vaporized may be liquid orsolid under standard temperature and pressure conditions (roomtemperature and atmospheric pressure). In some embodiments, the reactantbeing vaporized comprises an organic precursor, such as an organicamine, for example ethylene diamine (EDA). In some embodiments areactant may comprise an organic precursor selected from the group of1,2-diaminoethane (1), 1,3-diaminopropane (1), 1,4-diaminobutane (1),1,5-diaminopentane (1), 1,2-diaminopropane (1), 2,3-butanediamine,2,2-dimethyl-1,3-propanediamine (1).

In some embodiments the substrate is contacted with a second vapor phaseprecursor, or reactant, for a second exposure period. In someembodiments the second precursor may be vaporized at a fourthtemperature to form the second vapor phase precursor. In someembodiments the second reactant vapor is transported to the substratethrough a gas line at a second temperature. In some embodiments thefifth transportation temperature is higher than the first vaporizationtemperature. In some embodiments the substrate may be contacted with thesecond vapor phase precursor at a sixth temperature that is higher thanthe fourth temperature. In some embodiments the sixth temperature may besubstantially the same as the third temperature at which the first vaporphase precursor contacts the substrate.

In some embodiments the second precursor exposure period is from about0.05 seconds to about 5.0 seconds, about 0.1 seconds to about 3 secondsor about 0.2 seconds to about 1.0 seconds. The optimum exposure periodcan be readily determined by the skilled artisan based on the particularcircumstances.

In some embodiments a polyamide film of a desired thickness is depositedon a substrate. The skilled artisan will appreciate that deposition of apolyamide film is the result of the above-described contacting actions,rather than a separate action. In some embodiments, the above-describedcontacting actions may be considered a deposition cycle. In someembodiments a deposition cycle may repeated until an organic film of adesired thickness is selectively deposited. Such a deposition cycle canbe repeated until a film of sufficient thickness is left on thesubstrate and the deposition is ended. The deposition cycle can includeadditional acts, need not be in the same sequence nor identicallyperformed in each repetition, and can be readily extended to morecomplex vapor deposition techniques. For example, a deposition cycle caninclude additional reactant supply processes, such as the supply andremoval (relative to the substrate) of additional reactants in eachcycle or in selected cycles. Though not shown, the process mayadditionally comprise treating the deposited film to form a polymer (forexample, UV treatment, annealing, etc.).

Subsequent Processing

In some embodiments further processing may be carried out subsequent tothe selective deposition process. For example, in some embodiments thesubstrate may be subjected to an etch process to remove at least aportion of the deposited organic film. In some embodiments an etchprocess subsequent to selective deposition of the organic film mayremove deposited organic material from both the first surface and thesecond surface of the substrate. In some embodiments the etch processmay be isotropic.

In some embodiments the etch process may remove the same amount, orthickness, of material from the first and second surfaces. That is, insome embodiments the etch rate of the organic material deposited on thefirst surface may be substantially similar to the etch rate of theorganic material deposited on the second surface. Due to the selectivenature of the deposition processes described herein, the amount oforganic material deposited on the second surface of the substrate may besubstantially less than the amount of material deposited on the firstsurface of the substrate. Therefore, an etch process may completelyremove deposited organic material from the second surface of thesubstrate while deposited organic material may remain on the firstsurface of the substrate.

In some embodiments the etch process may comprise an etch process knownin the art, for example a dry etch process such as a plasma etchprocess. In some embodiments the etch process may comprise exposing thesubstrate to hydrogen atoms, hydrogen radicals, hydrogen plasma, orcombinations thereof. For example, in some embodiments the etch processmay comprise exposing the substrate to a plasma generated from H₂ usinga power from about 10 W to about 5000 W, from about 25 W to about 2500W, from about 50 W to about 500 W, or preferably from about 100 W toabout 400 W.

In some embodiments the etch process may comprise exposing the substrateto a plasma. In some embodiments the plasma may comprise oxygen atoms,oxygen radicals, oxygen plasma, or combinations thereof. In someembodiments the plasma may comprise hydrogen atoms, hydrogen radicals,hydrogen plasma, or combinations thereof. In some embodiments the plasmamay also comprise noble gas species, for example Ar or He species. Insome embodiments the plasma may consist essentially of noble gasspecies. In some instances the plasma may comprise other species, forexample nitrogen atoms, nitrogen radicals, nitrogen plasma, orcombinations thereof. In some embodiments the etch process may compriseexposing the substrate to an etchant comprising oxygen, for example O₃.In some embodiments the substrate may be exposed to an etchant at atemperature of between about 30° C. and about 500° C., preferablybetween about 100° C. and about 400° C. In some embodiments the etchantmay be supplied in one continuous pulse or may be supplied in multipleshorter pulses.

A skilled artisan can readily determine the optimal exposure time,temperature, and power for removing the desired amount of depositedorganic material from the substrate.

EXAMPLE 1

Sample polyimide thin films were deposited on a number of substratesaccording to selective deposition processes described herein. 200 mmsilicon wafers having tungsten (W) features alternated with siliconoxide surfaces were used as substrates. The width of the tungstenfeatures was 250 nm with a pitch of approximately 600 nm. The polyimidedeposition processes were performed in a Pulsar 3000® cross-flow ALDreactor connected with PRI cluster tool.

A first batch of sample polyimide films were deposited according to theprocesses described herein using DAH as a first vapor phase reactant andPMDA as a second vapor phase reactant. The DAH first reactant wassupplied at 45° C. by an N₂ carrier gas having a flow rate of 450 sccm.The DAH pulse time was 5 seconds and the DAH pure time was 4 seconds.The PMDA second reactant was supplied to the reaction chamber at 180° C.by an N₂ carrier gas having a flow rate of 450 sccm. The PMDA pulse timewas 11 seconds and the PMDA purge time was 4 seconds. The reaction orsubstrate temperature was 160° C. Polyimide films were deposited usingbetween 25 and 100 deposition cycles.

A second batch of sample polyimide films were deposited according to theprocesses described herein using substantially similar conditions as thefirst batch, but having a reaction temperature of 190° C. Polyimidefilms were deposited using between 250 and 1000 deposition cycles.

The thicknesses of the polyimide film samples were measured usingscanning transmission electron microscopy. The first batch of polyimidefilms were found to have thicknesses between 5 nm for a process having25 deposition cycles and 40 nm for a process having 100 depositioncycles with a growth rate of about 4-6 Å/cycle. The amount of polyimidedeposited on the W surfaces of the substrate was substantially the sameas the amount of polyimide deposited on the silicon oxide surface.Therefore, the deposition was not selective at a reaction temperature of160° C. for this recipe.

The second bath of polyimide films were found to have thicknessesranging from about 7 nm for a process having 250 cycles to about 28 nmfor a process having 1000 cycles on the W surfaces. Polyimide filmthicknesses on the silicon oxide surfaces ranged from about 4 nm for aprocess having 250 cycles to about 6 nm for a process having 1000cycles. Therefore, the polyimide deposition was selective at a reactiontemperature of 190° C. The growth rate on the W surfaces was about 0.2-1Å/cycle. FIG. 4 shows cross-sectional STEM images of polyimide filmsselectively deposited on W surfaces relative to SiO₂ surfaces utilizingbetween 250 and 1000 deposition cycles.

EXAMPLE 2

A first sample polyamide film was deposited on a 200 mm silicon waferhaving patterned tungsten (W) features alternated with silicon oxidesurfaces. A second sample polyamide film was deposited on a crystallinesilicon wafer having 1.5 nm of native oxide. The samples were depositedaccording to the processes described herein using adipoyl chloride (AC)as a first vapor phase reactant and ethylene diamine (EDA) as a secondvapor phase reactant. The AC first reactant was vaporized at atemperature of 50° C. and supplied to the reaction chamber at atemperature of 65° C. with a line flow of 500 sccm. The AC pulse andpurge times were 2.5 seconds. A pulsing pressure of about 180 Torr wasused and the conduit through which the AC was supplied was fitted with aline filter. The ED second reactant was supplied at room temperaturewith pulse and purge times of ⅕ seconds. A pulsing pressure of about 100Torr was used and the conduit through which the ED was supplied was notfitted with a line filter. The temperature of the substrate was 95° C.and the process included 1000 deposition cycles.

The resultant films were characterized by spectroscopic ellipsometry andthickness verification was done with x-ray reflectometry. The growthrate for the polyamide film deposited on the crystalline siliconsubstrate with 1.5 nm of native oxide was found to be about 0.5 Å/cycleand 1σ a thickness non-uniformity was around 3% for 300 mm mapping with3 mm edge exclusion. The film was found to have a thickness of about 9nm, as shown in FIG. 5A.

It was found that almost no polyamide was deposited on the native oxidesurface of the W patterned wafer, while polyamide material is clearlyvisible on the W lines, as shown in FIG. 5B. Therefore, the polyamidedeposition of the W patterned wafer was found to be selective.

EXAMPLE 3

A sample polyimide film was selectively deposited on a 200 mm siliconwafer having patterned tungsten (W) features alternated with siliconoxide surfaces according to the processes described herein using DAH asa first vapor phase reactant and PMDA as a second vapor phase reactant.The DAH first reactant was supplied at 45° C. by an N₂ carrier gashaving a flow rate of 450 sccm. The DAH pulse time was 5 seconds and theDAH pure time was 4 seconds. The PMDA second reactant was supplied tothe reaction chamber at 180° C. by an N₂ carrier gas having a flow rateof 450 sccm. The PMDA pulse time was 11 seconds and the PMDA purge timewas 4 seconds. The reaction temperature was 190° C. The polyimide samplefilm was deposited using 1000 deposition cycles. The polyimide wasdeposited on the W surface, with a film thickness of about 30 nm. Asubstantially lesser amount of polyimide was deposited on the siliconoxide surface, about 4 nm, as shown in FIG. 6A.

The sample polyimide film was then etched with H2 plasma generated using100 W at a temperature of 300° C. for 40 seconds. The flow rate of theH₂ gas was 100 sccm. As shown in FIGS. 6B-C, polyimide was completelyremoved from the silicon oxide surface while a polyimide film having athickness of about 9 nm was left on the W surface.

EXAMPLE 4

Sample polyamide (2,6) films were deposited according to processesdescribed herein. Adipoyl chloride (AC) and ethylene diamine (EDA) wereused as reactants. The AC reactant was heated to a temperature of 50° C.and vaporized. The EDA reactant was vaporized at room temperature, withneedle valves being used to control the reactant dose. Nitrogen was usedas both a carrier gas for the reactants and a purge gas. Both thecarrier and purge gas flow was about 500 sccm. Samples were deposited on300 mm crystalline silicon wafers having a surface comprising about 1.5nm native oxide. For each sample 200 deposition cycles were carried out.The thickness of the deposited films was measured using an ellipsometer.

Sample films were deposited with the EDA contacting times varied between0 and 3 seconds at a deposition temperature of 71° C. As seen in FIG.7A, the growth rate per cycle of the polyamide films increased withincreasing EDA contacting time, reaching about 0.5 Å/cycle for an EDAcontacting time of 3 seconds.

Similarly, sample films were deposited with the AC contacting timesvaried between 0 and 5 seconds at a deposition temperature of 71° C. Asseen in FIG. 7B, the growth rate per cycle of the polyamide filmsincreased with increasing AC contacting time, reaching a about 0.5Å/cycle for an AC contacting time of 5 seconds

The precursor and reaction by-product removal, or purge, time waslikewise varied for sample polyamide films. The removal times werevaried between 2 and 10 seconds. As seen in FIG. 7C, the growth rate percycle decreased with increasing removal time, although the effectappeared to be relatively small.

The relationship between growth rate and deposition temperature was alsoinvestigated. Sample films were prepared with deposition temperaturesvarying from 50° C. to 71° C. As can be seen in FIG. 7D, growth rate percycle increased with decreasing deposition temperature, reaching agrowth rate of 1.4 Å/cycle at a deposition temperature of 50 ° C.

FIG. 8A shows a thickness map for a sample polyamide films deposited at71° C. FIG. 8B shows a thickness map for a sample polyamide filmsdeposited at 50° C. The 1σ non-uniformity of the sample film depositedat 71° C. was found to be 3.0%, while the 1σ non-uniformity of thesample film deposited at 50° C. was found to be 2.6%. Further, thenon-uniformity occurred primarily at the edges of the wafer, thereforethe deposited sample films were found to be considerably uniform.

Although certain embodiments and examples have been discussed, it willbe understood by those skilled in the art that the scope of the claimsextend beyond the specifically disclosed embodiments to otheralternative embodiments and/or uses and obvious modifications andequivalents thereof.

What is claimed is:
 1. A process for depositing a polyamide film on asubstrate, the process comprising one or more deposition cyclescomprising: contacting the substrate with a first vapor phase precursorcomprising 5 or fewer carbon atoms; contacting the substrate with asecond vapor phase precursor comprising 3 or fewer carbons; whereincontacting the substrate with the first and second vapor phaseprecursors forms the polyamide film of a desired thickness.
 2. Theprocess of claim 1, wherein the process is a vapor deposition process.3. The process of claim 2, wherein the process is a molecular layerdeposition (MLD) process.
 4. The process of claim 1, wherein thesubstrate comprises a first surface and a second.
 5. The process ofclaim 4, wherein the polyamide film is formed selectively on the firstsurface of the substrate relative to the second surface of thesubstrate.
 6. The process of claim 5 further comprising subjecting thesubstrate to an etch process, wherein the etch process has a chemistryfor removal of organic material and removes substantially all of anydeposited polyamide film from the second surface of the substrate anddoes not remove substantially all of the deposited polyamide film fromthe first surface of the substrate.
 7. The process of claim 6, whereinthe etch process comprises exposing the substrate to hydrogen atoms,hydrogen radicals, hydrogen plasma, or combinations thereof.
 8. Theprocess of claim 6, wherein the etch process comprises exposing thesubstrate to oxygen atoms, oxygen radicals, oxygen plasma, orcombinations thereof.
 9. The process of claim 5, wherein the secondsurface comprises an inorganic dielectric surface.
 10. The process ofclaim 5, wherein the first surface comprises a metal oxide, elementalmetal, or metallic surface.
 11. The process of claim 5, wherein thefirst surface comprises tungsten.
 12. The process of claim 5, whereinthe second surface comprises silicon.
 13. The process of claim 12,wherein the second surface comprises SiO₂.
 14. The process of claim 1,wherein the first vapor phase precursor comprises chlorine ordicarboxylic acid.
 15. The process of claim 14, wherein the first vaporphase precursor comprises adipoyl chloride (AC).
 16. The process ofclaim 1, wherein the first vapor phase precursor is selected from thegroup consisting of oxalyl chloride (I), malonyl chloride, and fumarylchloride.
 17. The process of claim 1, wherein the second vapor phaseprecursor comprises an amine.
 18. The process of claim 17, wherein thesecond vapor phase precursor comprises ethylene diamine (EDA).
 19. Theprocess of claim 1, wherein the second vapor phase precursor is selectedfrom the group consisting of 1,2-diaminoethane (1), 1,3-diaminopropane(1), 1,4-diaminobutane (1), 1,5-diaminopentane (1), 1,2-diaminopropane(1), and 2,3-butanediamine, 2,2-dimethyl-1,3-propanediamine (1).